Journal of Physical Chemistry C
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2024
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IF 3.3
Cong Fu,Lingfang Liu,Guofeng Zhao
The effect of noble metal cocatalyst loading on the concentration of surface-reaching photoexcited charges on semiconductors is an interesting and important issue in photocatalysis. Herein, through in situ diffuse-reflectance infrared spectroscopy (DRIFTS), an adsorbate (methanol) surface elementary reaction kinetic analysis method has been exploited to track the concentration of surface-reaching photoholes in a series of Ag/TiO2 nanoparticles with varied Ag loading. The photocatalytic oxidation of adsorbed methanol species on the Ag/TiO2 surface proceeds via first-order reaction kinetics. Thus, the measured reaction rate constants directly reflect the concentration of surface-reaching photoholes under light irradiation. By determining the specific reaction rate constants for methanol oxidation on the Ag/TiO2 surface, we discover that the concentration of surface-reaching photoholes under light irradiation exhibits a volcano-shaped dependence on the Ag loading. Under the optimized Ag loading, it could be found that the concentration of surface-reaching photoholes on Ag/TiO2 surface is nearly 1.5 times greater than that of the pristine TiO2 surface. These results provide, for the first time, unambiguous experimental evidence for the significance of modification with suitable noble metal cocatalysts on regulation of surface-reaching photoexcited charges in semiconductor-based photocatalysis.
研究领域:
材料科学
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光催化领域
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2014
·Vol. 73
·期 2
·299-305
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IF 1.547
Wang Zhen-Zhen,Zhai Shang-Ru,Zhang Feng,Xiao Zuo-Yi,Zhai Bin,An Qing-Da
This work presented a novel, facile, cost-effective and environmentally friendly approach for the preparation of magnetic core–shell structured catalyst i.e. Fe 3 O 4 @SN–Ag (abbreviation of Fe 3 O 4 @SiO 2 –NH 2 –Ag). During the process of preparation, Ag nanoparticles were in situ generated with amino groups in the surface of Fe 3 O 4 @SN serving as green reductant and stabilizer in the absence of any additional toxic reductant or organic reagent. Magnetic core, Fe 3 O 4 , was easily prepared through solvothermal method. The subsequent coating and surface amino functionalization of SiO 2 was accomplished via one-pot sol–gel method, which was green and time-saving. What’s more, the resulting catalyst exhibited excellent catalytic property (the reaction was finished within 2 min) and reusability (reused at least seven times) in the reduction of 4-nitrophenol.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
Small
·
2015
·Vol. 11
·期 20
·2454-2462
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IF 8.368
Peng Du,Pengtao Jing,Di Li,Yinghui Cao,Zhenyu Liu,Zaicheng Sun
Localized surface plasmon resonance (LSPR), light scattering, and lowering the series resistance of noble metal nanoparticles (NPs) provide positive effect on the performance of photovoltaic device. However, the exciton recombination on the noble metal NPs accompanying above influences will deteriorate the performance of device. In this report, surface-modified Ag@oxide (TiO 2 or SiO 2 ) nanoprisms with 1–2 nm shell thickness are developed. The thin film composed of P3HT/Ag@oxides and P3HT:PCBM/Ag@oxides is investigated by absorption, photoluminescence (PL), and transient absorption spectroscopy. The results show a significant absorption, PL enhancement, and long-lived photogenerated polaron in the P3HT/Ag@TiO 2 film, indicating the increase of photogenerated exciton population by LSPR of Ag nanoprisms. In the case of P3HT/Ag nanoprisms, partial PL quench and relatively short-lived photogenerated polaron are observed. That indicates that the oxides layer can effectively avoid the exciton recombination. When the Ag@oxide nanoprisms are introduced into the active layer of P3HT:PCBM photovoltaic devices, about 31% of power conversion efficiency enhancement is obtained relative to the reference cell. All these results indicate that Ag@oxides can enhance the performance of the cell, at the same time the ultrathin oxide shell prevents from the exciton recombination.
研究领域:
材料科学
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光学工程
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能源科学
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DOI
PubMed
高影响因子
CARBON
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2024
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IF 10.5
Lu Xu,Ranran Si,Qi Ni,Jiaan Chen,Jiale Zhang,Qing-Qing Ni
Simultaneously achieving excellent shielding effectiveness (SE) and high absorption rate of flexible electromagnetic interference (EMI) shielding materials has become a growing demand for the new generation of highly integrated electronic devices. This study constructed a double-layer polydimethylsiloxane (PDMS) EMI shielding composite film, with the upper layer using Ni-plated carbon fiber (Ni@CF) as the high absorption loss part and the lower layer using Ag-plated graphene fiber (Ag@GF) as the reflection attenuation part. Due to the synergistic magnetic/dielectric loss effect in the upper layer, high electrical conductivity in the lower layer, and the shielding mechanism of “absorption-reflection-reabsorption” induced by the double-layer structure, this composite film achieves efficient EMI shielding performance and high absorption characteristics in the X-band. The EMI SE values of the 2 mm thick film containing 0.03 wt% Ni@CF and 1.2 wt% Ag@GF reach 33.7 dB, while shielding effectiveness of reflection ( SE R ) and absorption ( SE A ) is 0.8 dB and 32.9 dB, respectively. This result means that the composite film only reflects 17.2 % of the microwaves while shielding 99.9 % and absorbs nearly 82.7 %, exhibiting a significant absorption-dominated shielding mechanism. This flexible and efficient shielding film with a high absorption rate suits portable and wearable intelligent electronic products to reduce secondary electromagnetic pollution.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2025
·
IF 5.6
Yingying Xu,Mengyao Li,Yingjiu Zhang,Hongzhang Song,Haoshan Hao
A series of Bi 2 Sr 2 Co 2 O y (BSCO), Bi 2 (Sr 2/3 Ba 2/3 Ca 2/3 )Co 2 O y (BSBCCO), Bi 1.9 Cu 0.1 (Sr 2/3 Ba 2/3 Ca 2/3 )Co 2 O y (BCSBCCO) and Bi 1.8 Ag 0.2 (Sr 2/3 Ba 2/3 Ca 2/3 )Co 2 O y (BASBCCO) ceramic samples were prepared to optimize the thermoelectric properties of BSCO by high entropy doping combined with Cu/Ag doping. High entropy doping improves the carrier mobility significantly, due to a sintering effect in liquid phase and an additional conduction path. Cu/Ag acceptor doping increases the carrier concentration and Seebeck coefficients. Both them enhance the electrical transport performance of doped samples effectively. Specially, the random distribution of several different cations caused by high entropy doping and Cu/Ag doping can enhance the phonon scattering, which greatly reduces the thermal conductivity of doped samples. Finally, the thermoelectric figure of merit ( ZT ) value of the BASBCCO sample is improved to 0.36 at 923 K on the basis of high entropy doped BSBCCO ( ZT = 0.28 at 923 K), which is twice that of the pristine sample.
研究领域:
材料科学
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热电材料
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DOI
高影响因子
RSC Advances
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2014
·Vol. 5
·期 9
·6413-6418
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IF 3.708
Hui Li,Guoping Zhang,Libo Deng,Rong Sun,Xing Ou-Yang
Thermally responsive copolymer P(NIPAm-co-NMA) was prepared via a radical copolymerization and spun into nanofibers using electrospinning. After thermal crosslinking, the electrospun fibers were modified using KH590 and silver nanoparticles were introduced onto the fiber surface using a chemical plating method. The electrical resistance of the composite fibers containing 65.5% of silver at different temperatures was investigated and it was found that the resistance dropped by ∼60% as the temperature increased from 42 °C to 46 °C, which is consistent with the solubility transition of PNIPAm with the change of temperature as revealed by differential scanning calorimetry (DSC) measurement.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Zhichao Shang,Zhongxiang Yang,Yang Xiao,Xiaohong Wang
The various ordered mesoporous Ag/CeO 2 catalysts were successfully prepared using a facile silica-templated solution combustion synthesis method (TSCS). Utilizing X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), photoluminescence (PL) and UV–vis diffuse reflectance spectrometry (DRS), etc., the morphological, structural, crystalline, surface and optical properties of Ag/CeO 2 were investigated. It was found that the removal of the template (SiO 2 ) resulted in the formation of ultrafine mesoporous Ag/CeO 2 composites, and the specific surface area increased to 98.6 m 2 /g. The 15 % Ag/CeO 2 composite showed the best photocatalytic performance (97 % at 120 min), which was approximately 10 times higher as compared to the conventional SCS (Solution Combustion Synthesized) CeO 2 . In addition, a mechanism of the photocatalytic degradation of Rhodamine B (RhB) was proposed, where the reactive species ·O 2 − and h + played important roles in the degradation of pollutants.
研究领域:
材料科学
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环境科学
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催化
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DOI
高影响因子
CHEMOSPHERE
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2019
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IF 5.108
Ying Zeng,Na Guo,Xingjian Xu,Yong Yu,Quanying Wang,Na Wang,Xuerong Han,Hongwen Yu
WO 3 @MoS 2 /Ag (HW@MA) hollow tubes were successfully engineered to photodegrade bisphenol A (BPA) combined with peroxymonosulfate (PMS) for the first time. XRD, XPS, TEM and SEM were conducted. The HW@MA tubes present excellent photocatalytic performance on the removal of BPA. The intermediate products of BPA were investigated by GC-MS analysis and the degradation pathway was proposed. To explore the transferred mechanism of photoproduced carriers, the electron paramagnetic resonance (EPR) technique was carried out. The results revealed that the superoxide radical ( O 2 − ), hydroxyl radical ( OH), sulfate radical ( SO 4 − ) were the main active radicals. Moreover, the formed schottky junctions enhanced the separation efficiency of photoinduced electron-hole pairs. Besides, the effect of the photocatalysts’ dosage, PMS concentration, pH of the initial solution and co-existing anions on the BPA degradation were investigated.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2018
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IF 3.927
Hui Xu,Yunfang Huang,Dan Luo,Xiaomin Yang,Shao Jin,Qiyao Guo,Yuezhu Zhao,Yu Fang,Yuelin Wei,Jihuai Wu
In this work, multiple heterojunction Ag/Bi/BiOCl 0.8 Br 0.2 photocatalysts with novel porous micro-flower structure were fabricated via a facile one-step solvothermal route and characterized systematically. The TEM and HRTEM images clearly showed the heterogeneous nanostructures at the interface between Ag/Bi and BiOCl 0.8 Br 0.2 . The as-prepared Ag/Bi/BiOCl 0.8 Br 0.2 composites displayed a strong optical absorption in the region of 250–1500 nm, especially in the unexploited near infrared region which accounts for most of the sunlight. The multiple heterojunction photocatalyst exhibited an outstanding photocatalytic activity for the degradation of Rhodamine B under the UV, visible and NIR light irradiation, respectively. The highly enhanced photocatalytic activity was attributed to the synergistic effects, including the reduced band gap, the surface plasmon resonance effect, efficient charge separation of photo-generated electron-holes. On the basis of the radical species trapping experiments, the holes and superoxide radicals were confirmed to be the mainly active species involved in the degradation of Rhodamine B under the NIR light irradiation. This study provides a novel strategy for designing highly performance plasmonic photocatalysts under the whole solar light irradiation.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2022
·
IF 12.92
Anxiang Guan,Yueli Quan,Yangshen Chen,Zhengzheng Liu,Junbo Zhang,Miao Kan,Quan Zhang,Haoliang Huang,Linping Qian,Linjuan Zhang,Gengfeng Zheng
The electrocarboxylation reaction is an attractive means to convert CO 2 into valuable chemicals under ambient conditions, while it still suffers from low efficiency due to the high stability of CO 2 . In this work, we report a double activation strategy for simultaneously activating CO 2 and acetophenone by silver-doped CeO 2 (Ag-CeO 2 ) nanowires, featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO 2 . Compared to the Ag foil, Ag nanoparticles and CeO 2 nanowires, the Ag-CeO 2 nanowire catalyst allowed to reduce the onset potential difference between CO 2 and acetophenone activation, thus enabling efficient electrocarboxylation to form 2-phenyllactic acid. The Faradaic efficiency for producing 2-phenyllactic acid reached 91% at −1.8 V versus Ag/AgI. This double activation strategy of activating both CO 2 and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO 2 fixation for higher-value electrocarboxylation.
研究领域:
化学
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环境科学
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Zhengjie Su,Xinru Wu,Dong-Hau Kuo,Baoqian Yang,Binghong Wu,Longyan Chen,Pengkun Zhang,Jinguo Lin,Dongfang Lu,Xiaoyun Chen
Herein, an Ag/S co-doped Bi2O3-based sulfur oxide catalyst was prepared via a facile green method. The Ag/S–Bi2O3 catalyst with suitable Ag/S doping demonstrated super visible light photocatalytic hydrogen evolution (PHE) at 7.52 mmol g−1 h−1, with an apparent quantum efficiency (AQE) of 8.67% at 420 nm. Ag/S co-doping can adjust the energy band structure of an oxidation type Bi2O3 catalyst, converting it into a visible light hydrogen production catalyst suitable for hydrogen production. Sulfur doping adjusts the content of oxygen vacancies to enhance the surface active sites, and the introduction of noble metal silver endows the catalyst with more excellent electrical conductivity and electron trapping ability. Thus, Bi2O3 with Ag/S co-doping produced a suitable energy band structure, enhanced the content of oxygen vacancies and the number of surface active sites, and endowed the catalyst with excellent electrical conductivity and electron trapping ability, significantly producing catalysts with excellent visible light PHE activity. Furthermore, Ag/S–Bi2O3-3 exhibited super visible light PHE activity and excellent stability and persistence and is expected to play a potential role in the field of PHE reactions (PHERs).
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Yueshou Zhang,Lichun Yang,Yulin Xu,Haiting Ren,Shi Yin,Yan Sun,Yongjun Hu
Rapid and sensitive detection of phosphate is of great significance for ensuring water safety and preventing eutrophication. In this study, we prepared Au@PATP@Ag NRs core-shell structures using 4-aminothiophenol (PATP) as an internal standard signal molecule to enhance the stability of the SERS signal. Based on the phosphate-induced decomposition of ZIF-8 and the protective effect of ZIF-8 on the internal Au@PATP@Ag NRs, a phosphate SERS sensor (Au@PATP@Ag@ZIF-8) with high sensitivity, selectivity and stability was designed. This method exhibited a good linear range of 0.1–125 μM and a detection limit of 30 nM. Furthermore, the developed sensor (Au@PATP@Ag@ZIF-8) was effectively applied to assess PO 4 3− in tap water samples, achieving recoveries between 97.44% and 104.54%. With its simple, fast and sensitive features, this method of phosphate detection in water provides a direction for the research and practical application of phosphate detection.
研究领域:
环境科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
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